1. Field of the Invention
This invention relates to the design of butterfly valves and in particular to the design of the disk shaped valve plate of butterfly valves.
2. Prior Art
Prior art butterfly valves have employed disks having strengthening ribs as shown in the U.S. Pat. to Henry Masheder No. 2,986,373 issued May 30, 1961. Such strengthening ribs typically span the major portion of the face of the disk and are parallel to the direction of fluid flow. The ribs may be located on one or both sides of the disk.
It is the general objective of all butterfly valves to provide an effective valve seal assembly which results in a minimum pressure drop across the valve, requires minimum force to operate the valve and produces minimum turbulence and noise.
It is thus an object of the present invention to provide a butterfly valve which results in an improvement over prior art valves in each of the performance criteria referred to above.